1. Technical Field
The invention relates to semiconductor technology, and in particular relates to a semiconductor device and a method for fabricating the same.
2. Description of the Related Art
For semiconductor processing, ion implantation is commonly used for forming doped regions or features in various semiconductor devices. For example, ion implantation may be used for forming source/drain regions in an NMOS, PMOS, or CMOS. However, ion implantation has its drawbacks and limitations. Among them, when performing ion implantation on a target material such as a semiconductor layer in a semiconductor device, the semiconductor layer may be damaged due to a high impact of a dopant or etching when dopants are corrosive to the semiconductor layer. For example, it has been found that fluorine-containing dopants are corrosive to silicon-containing films. Consequently, material removal (or material loss) of the semiconductor layer as well as reduction in thickness (or height) of the semiconductor layer may occur. This may complicate subsequent processes by causing problems such as over-etching into the semiconductor device beneath the semiconductor layer. As a result, the structure and performance of features already formed beneath the semiconductor layer in the semiconductor device may be damaged.
Therefore, a novel method for fabricating a semiconductor device is needed for improving or solving the aforementioned problems.